server/mapping.c

   1 /*
   2  * Server-side file mapping management
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <unistd.h>
  13
  14 #include "winnt.h"
  15 #include "winbase.h"
  16
  17 #include "handle.h"
  18 #include "thread.h"
  19 #include "request.h"
  20
  21 struct mapping
  22 {
  23     struct object   obj;             /* object header */
  24     int             size_high;       /* mapping size */
  25     int             size_low;        /* mapping size */
  26     int             protect;         /* protection flags */
  27     struct file    *file;            /* file mapped */
  28     int             header_size;     /* size of headers (for PE image mapping) */
  29     void           *base;            /* default base addr (for PE image mapping) */
  30     struct file    *shared_file;     /* temp file for shared PE mapping */
  31     int             shared_size;     /* shared mapping total size */
  32     struct mapping *shared_next;     /* next in shared PE mapping list */
  33     struct mapping *shared_prev;     /* prev in shared PE mapping list */
  34 };
  35
  36 static int mapping_get_fd( struct object *obj );
  37 static int mapping_get_info( struct object *obj, struct get_file_info_reply *reply );
  38 static void mapping_dump( struct object *obj, int verbose );
  39 static void mapping_destroy( struct object *obj );
  40
  41 static const struct object_ops mapping_ops =
  42 {
  43     sizeof(struct mapping),      /* size */
  44     mapping_dump,                /* dump */
  45     no_add_queue,                /* add_queue */
  46     NULL,                        /* remove_queue */
  47     NULL,                        /* signaled */
  48     NULL,                        /* satisfied */
  49     NULL,                        /* get_poll_events */
  50     NULL,                        /* poll_event */
  51     mapping_get_fd,              /* get_fd */
  52     no_flush,                    /* flush */
  53     mapping_get_info,            /* get_file_info */
  54     NULL,                        /* queue_async */
  55     mapping_destroy              /* destroy */
  56 };
  57
  58 static struct mapping *shared_first;
  59
  60 #ifdef __i386__
  61
  62 /* These are always the same on an i386, and it will be faster this way */
  63 # define page_mask  0xfff
  64 # define page_shift 12
  65 # define init_page_size() do { /* nothing */ } while(0)
  66
  67 #else  /* __i386__ */
  68
  69 static int page_shift, page_mask;
  70
  71 static void init_page_size(void)
  72 {
  73     int page_size;
  74 # ifdef HAVE_GETPAGESIZE
  75     page_size = getpagesize();
  76 # else
  77 #  ifdef __svr4__
  78     page_size = sysconf(_SC_PAGESIZE);
  79 #  else
  80 #   error Cannot get the page size on this platform
  81 #  endif
  82 # endif
  83     page_mask = page_size - 1;
  84     /* Make sure we have a power of 2 */
  85     assert( !(page_size & page_mask) );
  86     page_shift = 0;
  87     while ((1 << page_shift) != page_size) page_shift++;
  88 }
  89 #endif  /* __i386__ */
  90
  91 #define ROUND_ADDR(addr) \
  92    ((int)(addr) & ~page_mask)
  93
  94 #define ROUND_SIZE(addr,size) \
  95    (((int)(size) + ((int)(addr) & page_mask) + page_mask) & ~page_mask)
  96
  97 /* get the fd to use for mmaping a file */
  98 inline static int get_mmap_fd( struct file *file )
  99 {
 100     struct object *obj;
 101     if (!(obj = (struct object *)file))
 102     {
 103         set_error( STATUS_INVALID_HANDLE );
 104         return -1;
 105     }
 106     return obj->ops->get_fd( obj );
 107 }
 108
 109 /* find the shared PE mapping for a given mapping */
 110 static struct file *get_shared_file( struct mapping *mapping )
 111 {
 112     struct mapping *ptr;
 113
 114     for (ptr = shared_first; ptr; ptr = ptr->shared_next)
 115         if (is_same_file( ptr->file, mapping->file ))
 116             return (struct file *)grab_object( ptr->shared_file );
 117     return NULL;
 118 }
 119
 120 /* allocate and fill the temp file for a shared PE image mapping */
 121 static int build_shared_mapping( struct mapping *mapping, int fd,
 122                                  IMAGE_SECTION_HEADER *sec, int nb_sec )
 123 {
 124     int i, max_size, total_size, pos;
 125     char *buffer = NULL;
 126     int shared_fd;
 127     long toread;
 128
 129     /* compute the total size of the shared mapping */
 130
 131     total_size = max_size = 0;
 132     for (i = 0; i < nb_sec; i++)
 133     {
 134         if ((sec[i].Characteristics & IMAGE_SCN_MEM_SHARED) &&
 135             (sec[i].Characteristics & IMAGE_SCN_MEM_WRITE))
 136         {
 137             int size = ROUND_SIZE( 0, sec[i].Misc.VirtualSize );
 138             if (size > max_size) max_size = size;
 139             total_size += size;
 140         }
 141     }
 142     if (!(mapping->shared_size = total_size)) return 1;  /* nothing to do */
 143
 144     if ((mapping->shared_file = get_shared_file( mapping ))) return 1;
 145
 146     /* create a temp file for the mapping */
 147
 148     if (!(mapping->shared_file = create_temp_file( GENERIC_READ|GENERIC_WRITE ))) goto error;
 149     if (!grow_file( mapping->shared_file, 0, total_size )) goto error;
 150     if ((shared_fd = get_mmap_fd( mapping->shared_file )) == -1) goto error;
 151
 152     if (!(buffer = malloc( max_size ))) goto error;
 153
 154     /* copy the shared sections data into the temp file */
 155
 156     for (i = pos = 0; i < nb_sec; i++)
 157     {
 158         if (!(sec[i].Characteristics & IMAGE_SCN_MEM_SHARED)) continue;
 159         if (!(sec[i].Characteristics & IMAGE_SCN_MEM_WRITE)) continue;
 160         if (lseek( shared_fd, pos, SEEK_SET ) != pos) goto error;
 161         pos += ROUND_SIZE( 0, sec[i].Misc.VirtualSize );
 162         if (sec[i].Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA) continue;
 163         if (!sec[i].PointerToRawData || !sec[i].SizeOfRawData) continue;
 164         if (lseek( fd, sec[i].PointerToRawData, SEEK_SET ) != sec[i].PointerToRawData) goto error;
 165         toread = sec[i].SizeOfRawData;
 166         while (toread)
 167         {
 168             long res = read( fd, buffer + sec[i].SizeOfRawData - toread, toread );
 169             if (res <= 0) goto error;
 170             toread -= res;
 171         }
 172         if (write( shared_fd, buffer, sec[i].SizeOfRawData ) != sec[i].SizeOfRawData) goto error;
 173     }
 174     free( buffer );
 175     return 1;
 176
 177  error:
 178     if (buffer) free( buffer );
 179     return 0;
 180 }
 181
 182 /* retrieve the mapping parameters for an executable (PE) image */
 183 static int get_image_params( struct mapping *mapping )
 184 {
 185     IMAGE_DOS_HEADER dos;
 186     IMAGE_NT_HEADERS nt;
 187     IMAGE_SECTION_HEADER *sec = NULL;
 188     int fd, filepos, size;
 189
 190     /* load the headers */
 191
 192     if ((fd = get_mmap_fd( mapping->file )) == -1) return 0;
 193     filepos = lseek( fd, 0, SEEK_SET );
 194     if (read( fd, &dos, sizeof(dos) ) != sizeof(dos)) goto error;
 195     if (dos.e_magic != IMAGE_DOS_SIGNATURE) goto error;
 196     if (lseek( fd, dos.e_lfanew, SEEK_SET ) == -1) goto error;
 197     if (read( fd, &nt, sizeof(nt) ) != sizeof(nt)) goto error;
 198     if (nt.Signature != IMAGE_NT_SIGNATURE) goto error;
 199
 200     /* load the section headers */
 201
 202     size = sizeof(*sec) * nt.FileHeader.NumberOfSections;
 203     if (!(sec = malloc( size ))) goto error;
 204     if (read( fd, sec, size ) != size) goto error;
 205
 206     if (!build_shared_mapping( mapping, fd, sec, nt.FileHeader.NumberOfSections )) goto error;
 207
 208     if (mapping->shared_file)  /* link it in the list */
 209     {
 210         if ((mapping->shared_next = shared_first)) shared_first->shared_prev = mapping;
 211         mapping->shared_prev = NULL;
 212         shared_first = mapping;
 213     }
 214
 215     mapping->size_low    = ROUND_SIZE( 0, nt.OptionalHeader.SizeOfImage );
 216     mapping->size_high   = 0;
 217     mapping->base        = (void *)nt.OptionalHeader.ImageBase;
 218     mapping->header_size = ROUND_SIZE( mapping->base, nt.OptionalHeader.SizeOfHeaders );
 219     mapping->protect     = VPROT_IMAGE;
 220
 221     /* sanity check */
 222     if (mapping->header_size > mapping->size_low) goto error;
 223
 224     lseek( fd, filepos, SEEK_SET );
 225     free( sec );
 226     return 1;
 227
 228  error:
 229     lseek( fd, filepos, SEEK_SET );
 230     if (sec) free( sec );
 231     set_error( STATUS_INVALID_FILE_FOR_SECTION );
 232     return 0;
 233 }
 234
 235
 236 static struct object *create_mapping( int size_high, int size_low, int protect,
 237                                       handle_t handle, const WCHAR *name, size_t len )
 238 {
 239     struct mapping *mapping;
 240     int access = 0;
 241
 242     if (!page_mask) init_page_size();
 243
 244     if (!(mapping = create_named_object( &mapping_ops, name, len )))
 245         return NULL;
 246     if (get_error() == STATUS_OBJECT_NAME_COLLISION)
 247         return &mapping->obj;  /* Nothing else to do */
 248
 249     mapping->header_size = 0;
 250     mapping->base        = NULL;
 251     mapping->shared_file = NULL;
 252     mapping->shared_size = 0;
 253
 254     if (protect & VPROT_READ) access |= GENERIC_READ;
 255     if (protect & VPROT_WRITE) access |= GENERIC_WRITE;
 256
 257     if (handle)
 258     {
 259         if (!(mapping->file = get_file_obj( current->process, handle, access ))) goto error;
 260         if (protect & VPROT_IMAGE)
 261         {
 262             if (!get_image_params( mapping )) goto error;
 263             return &mapping->obj;
 264         }
 265         if (!size_high && !size_low)
 266         {
 267             struct get_file_info_reply reply;
 268             struct object *obj = (struct object *)mapping->file;
 269             obj->ops->get_file_info( obj, &reply );
 270             size_high = reply.size_high;
 271             size_low  = ROUND_SIZE( 0, reply.size_low );
 272         }
 273         else if (!grow_file( mapping->file, size_high, size_low )) goto error;
 274     }
 275     else  /* Anonymous mapping (no associated file) */
 276     {
 277         if ((!size_high && !size_low) || (protect & VPROT_IMAGE))
 278         {
 279             set_error( STATUS_INVALID_PARAMETER );
 280             mapping->file = NULL;
 281             goto error;
 282         }
 283         if (!(mapping->file = create_temp_file( access ))) goto error;
 284         if (!grow_file( mapping->file, size_high, size_low )) goto error;
 285     }
 286     mapping->size_high = size_high;
 287     mapping->size_low  = ROUND_SIZE( 0, size_low );
 288     mapping->protect   = protect;
 289     return &mapping->obj;
 290
 291  error:
 292     release_object( mapping );
 293     return NULL;
 294 }
 295
 296 static void mapping_dump( struct object *obj, int verbose )
 297 {
 298     struct mapping *mapping = (struct mapping *)obj;
 299     assert( obj->ops == &mapping_ops );
 300     fprintf( stderr, "Mapping size=%08x%08x prot=%08x file=%p header_size=%08x base=%p "
 301              "shared_file=%p shared_size=%08x ",
 302              mapping->size_high, mapping->size_low, mapping->protect, mapping->file,
 303              mapping->header_size, mapping->base, mapping->shared_file, mapping->shared_size );
 304     dump_object_name( &mapping->obj );
 305     fputc( '\n', stderr );
 306 }
 307
 308 static int mapping_get_fd( struct object *obj )
 309 {
 310     struct mapping *mapping = (struct mapping *)obj;
 311     assert( obj->ops == &mapping_ops );
 312     return get_mmap_fd( mapping->file );
 313 }
 314
 315 static int mapping_get_info( struct object *obj, struct get_file_info_reply *reply )
 316 {
 317     struct mapping *mapping = (struct mapping *)obj;
 318     struct object *file = (struct object *)mapping->file;
 319
 320     assert( obj->ops == &mapping_ops );
 321     assert( file );
 322     return file->ops->get_file_info( file, reply );
 323 }
 324
 325 static void mapping_destroy( struct object *obj )
 326 {
 327     struct mapping *mapping = (struct mapping *)obj;
 328     assert( obj->ops == &mapping_ops );
 329     if (mapping->file) release_object( mapping->file );
 330     if (mapping->shared_file)
 331     {
 332         release_object( mapping->shared_file );
 333         if (mapping->shared_next) mapping->shared_next->shared_prev = mapping->shared_prev;
 334         if (mapping->shared_prev) mapping->shared_prev->shared_next = mapping->shared_next;
 335         else shared_first = mapping->shared_next;
 336     }
 337 }
 338
 339 int get_page_size(void)
 340 {
 341     if (!page_mask) init_page_size();
 342     return page_mask + 1;
 343 }
 344
 345 /* create a file mapping */
 346 DECL_HANDLER(create_mapping)
 347 {
 348     struct object *obj;
 349
 350     reply->handle = 0;
 351     if ((obj = create_mapping( req->size_high, req->size_low,
 352                                req->protect, req->file_handle,
 353                                get_req_data(), get_req_data_size() )))
 354     {
 355         int access = FILE_MAP_ALL_ACCESS;
 356         if (!(req->protect & VPROT_WRITE)) access &= ~FILE_MAP_WRITE;
 357         reply->handle = alloc_handle( current->process, obj, access, req->inherit );
 358         release_object( obj );
 359     }
 360 }
 361
 362 /* open a handle to a mapping */
 363 DECL_HANDLER(open_mapping)
 364 {
 365     reply->handle = open_object( get_req_data(), get_req_data_size(),
 366                                  &mapping_ops, req->access, req->inherit );
 367 }
 368
 369 /* get a mapping information */
 370 DECL_HANDLER(get_mapping_info)
 371 {
 372     struct mapping *mapping;
 373
 374     if ((mapping = (struct mapping *)get_handle_obj( current->process, req->handle,
 375                                                      0, &mapping_ops )))
 376     {
 377         reply->size_high   = mapping->size_high;
 378         reply->size_low    = mapping->size_low;
 379         reply->protect     = mapping->protect;
 380         reply->header_size = mapping->header_size;
 381         reply->base        = mapping->base;
 382         reply->shared_file = 0;
 383         reply->shared_size = mapping->shared_size;
 384         reply->drive_type  = get_file_drive_type( mapping->file );
 385         if (mapping->shared_file)
 386             reply->shared_file = alloc_handle( current->process, mapping->shared_file,
 387                                                GENERIC_READ|GENERIC_WRITE, 0 );
 388         release_object( mapping );
 389     }
 390 }